Chief of Staff Clint Reed was dismissed, Rubio, R-Fla., said in a statement late Saturday, because the staffer “had violated office policies regarding proper relations between a supervisor and their subordinates. I further concluded that this led to actions which in my judgment amounted to threats to withhold employment benefits.”

Reed is not mentioned by name in the statement, but a spokeswoman for Rubio confirmed that he was fired, USA Today reported.

“We have taken steps to ensure that those impacted by this conduct have access to any services they may require now or in the future,” Rubio said in the statement. “Pursuant to the wishes of those victimized by this conduct, we will not be disclosing any further details about the incidents which occurred. We will be formally notifying the appropriate congressional and Senate administrative offices of this matter when they return to work Monday morning.”

Reed has been Rubio’s chief of staff since January 2017, USA Today reported.